It is well known in the art to use feed rolls in the process of debarking, i.e. removing bark, from logs. Typically, such feed rolls are driven, by a motor or the like, and are situated at the input and output of debarkers for driving the logs through the debarker. Generally, two sets of flutes, each flute of one set having a corresponding flute on the other set with the corresponding flutes converging at inner portions thereof towards a central portion of the roll, are shaped to provide a recess in which the logs are supported and to grip and propel the logs through the debarker by rotation of the roll. As the log is generally supported and gripped through the inner portions, it is these portions that must provide most of the support and traction for advancing the log. Accordingly, these inner sections often have gripping members for gripping the log. At the same time, since the inner portions provide most of the support and traction, it is these inner portions, including the gripping members, that are most susceptible to wear and tear. Thus, the inner portions, and sometimes the entire flutes, must, eventually, be replaced. In traditional feed rolls, this necessitates removing the entire roll for replacing the flutes or inner sections thereof, which is, obviously, time consuming and inefficient, especially since the flutes are typically welded to the roll.
One solution for facilitating replacement and repair of flutes is to provide flutes for which at least a portion, and notably the inner flute portion which supports and grips the logs, are replaceable. For example, U.S. Pat. No. 6,253,813 issued to Kube et al. on Jul. 3, 2001 provides a feed roll in which there are removable flute attachments which are removably fastened on one side wall of the inner portions of the flutes and which have gripping members extending thereabove.
The flute attachments are attached with screws which extend through apertures in the flute attachment into threaded flute apertures, i.e. sockets, which extend through the inner portion of the flute. Thus, the attachments support and grip the log, which reduces wear and tear on the inner portions and then are simply moved and replaced when the attachments become worn. However, as the attachments are only attached on one side of the inner portions, the stress on the side to which the attachments are attached is disproportionate to that on the opposing side. Further, while the screws in Kube et al. are adapted for extending precisely through the inner portion of the flute to the side wall opposite the side wall to which the attachment is attached, this leaves little support for holding the attachment in place on the side wall opposite to the side wall to which the flute is attached. Thus the screws undergo great stresses and become a weak point of the design. Finally, as the attachment is mounted and extends alongside the inner flute portion in Kube, as opposed to covering the top of the inner flute portion, the configuration taught in Kube offers little protection for the top of the flute and the inner flute end, i.e. the end of the flute closest to the centre of the roll.
Accordingly, there is a need for an improved feed roll with replaceable flute attachments that obviates the difficulties described above.